Isoproterenol-induced impairment of heart function and remodeling are attenuated by the nonpeptide angiotensin-(1-7) analogue AVE 0991.

Abstract

The aim of this study was to evaluate the effects of AVE 0991 (AVE), a nonpeptide compound that mimics Ang-(1-7) actions, on cardiac remodeling. Heart hypertrophy and heart dysfunction were induced by isoproterenol (ISO) (2 mg/kg i.p./day for 7 days) in male Wistar rats. At the end of the 7-day period, the hearts were perfused according to the Langendorff method to evaluate cardiac function. The hearts, atria, and right and left ventricles wet weights were recorded, normalized for body weight and then expressed as muscle mass index (mg/g). In addition, serial sections from left ventricle were stained with hematoxylin-eosin for cell morphometry and with collagen-specific Masson's trichrome for detection of fibrosis. Immunofluorescence-labeling and confocal microscopy were used to investigate the distribution and deposition of collagen types I, III, VI, and fibronectin. AVE reduced the ISO-induced hypertrophy as quantified by myocyte diameter measurements (Control: 10.60+/-0.08 microm; ISO: 14.60+/-0.11 mum; ISO+AVE: 11.22+/-0.08 microm, n = 5). In addition, AVE markedly attenuated the increase of extracellular matrix proteins induced by ISO. AVE treatment also attenuated the decrease in systolic tension and +/-dT/dt and exacerbated the vasodilatation induced by ISO. These results show that AVE has a cardioprotective effect on ISO-induced cardiac remodeling.